If Prime Minister Malcolm Turnbull need rely upon several independent MPs to form government this will be no more than a recognition of electoral realities. Over the past 20 years there has been a steady decline in support for the major parties, neither of which is able to win a majority of support in its own right.

Between them the Coalition parties won just over 42% of primary votes, Labor just over 35%. That Labor seemed to peg level with the government is due to a heavy flow of preferences from the nearly 10% of Greens votes. This is now established as a consistent factor in national elections.

As long as preferences flow to the two major parties the current system can provide majority governments. But the past few elections have shown the capacity of strong locally based independents to defeat the major parties. Interestingly they come from a range of electorates, from inner-city Hobart (Andrew Wilkie) to outback Queensland (Bob Katter).

This year’s results also suggest that the Greens in Victoria and the Nick Xenophon Team (NXT) in South Australia might increase their representation by several seats at the next poll. The increased number of independents in the Senate is partly due to Turnbull’s remarkably ill-judged decision to force a double-dissolution election. But even in a half-Senate election, Pauline Hanson, Nick Xenophon and Derryn Hinch would probably have been elected.

Two overlapping factors are at play, neither of which is likely to reverse. The first is declining party loyalties: fewer people are developing lifelong political commitments as they still might do with football teams. This in turn is related to the fact that political divisions have become more complex, straddling both economic and social issues in ways that divide the major parties.

This is currently most apparent within the Liberals, where John Howard’s success in holding together social conservatives and economic liberals appears to be fraying. Of the current leadership only Julie Bishop seems to be able to straddle both camps. It is surprising she is not more often seen as a potential leader.

Thus the Liberals are challenged on the economic right by Liberal Democrats, while losing significant votes to a group of socially conservative Christian parties: Fred Nile’s Christian Democrats, and Family First, who may yet elect a senator. The rise of Hanson and NXT draws votes from all major parties through their ability to articulate the anger and frustration felt by the casualties of rapid social and economic change.

When backbenchers Cory Bernardi and George Christensen speak of a new conservative movement, it is unclear whether they wish to appeal to the disenfranchised on cultural or economic grounds. But they are moving into territory tilled by Clive Palmer in 2013 and Hanson this year.

For Labor the decline is greater. In the past 25 years, Labor has only twice polled more than 40% of primary votes, and needs spend considerable resources to fight off the Greens in its once-safe inner city seats. It is heroic of Chris Bowen to proclaim, as he did on Q&A following the election, that Labor will govern alone. It is also somewhat arrogant for a party that can only attract just over one-third of first-preference votes.

Unlike either Hanson or Xenophon, the Greens have become an established party with sufficient strength to elect at least one senator in every state. Their primary vote seemed to stabilise this year at just under 10%, which was not sufficient to win more than Adam Bandt’s seat of Melbourne. However, there are now several seats where they are viable, including at least one Liberal seat (Higgins in Melbourne) and several (Brisbane, Melbourne Ports and Richmond) that could become genuine three-way tussles.

In the short run, Labor will not wipe out the Greens, nor will the Greens replace Labor. It is in Labor’s interest to abandon the vitriol with which it attacked the Greens in the campaign, and acknowledge that any future Labor government will require close collaboration with the Greens, if not the formal arrangement accepted by Julia Gillard. When Labor politicians attack the Greens in the language of the Murdoch press they offend many of their own supporters.

Preferential voting was introduced into Australia to allow what have become the Liberal and National parties to compete for votes without losing seats to Labor. It is a much fairer system than the first-past-the-post used in the UK and the US, but it is becoming less representative as support for the major parties erodes.

As Jim Middleton has argued it may be time to look seriously at New Zealand’s model of proportional representation, which has provided a better reflection of the popular will and more stable governments than has become the case in Australia.